An apparatus for driving a scattered radiation grid of a diagnostic X-ray system is known for instance from German Patent 44 01 939 C1.
In a diagnostic radiology system, in particular a diagnostic X-ray system, a scattered radiation grid is disposed between a radiation source and a detection element, such as an X-ray film. This scattered radiation grid typically has a plurality of individual laminations and serves to absorb the scattered radiation that occurs when radiation is passed through an object to be irradiated, in particular a part of a human body. Image quality is enhanced because of the absorption of the scattered radiation. If the scattered radiation grid with the individual laminations of absorbent material is disposed in stationary fashion, such arrangement may produce interfering lines or marks on the X-ray film. The scattered radiation grid is therefore typically put into linear motion. From DE 44 01 939 C1, a tumbling or wobble bearing is provided. For a comparatively simple construction, the wobble bearing brings about a uniform motion of the scattered radiation grid even at the turning point.
One such scattered radiation grid has a mass of up to several kilograms. By way of the wobble bearing and the drive unit, in particular a controllable electric motor, restoring forces are therefore transmitted to a corresponding mount and hence to the entire diagnostic X-ray system. The forces can cause vibrations that adversely affect the image sharpness.
In German Patent Disclosure DE 698 05 733 T2, a diagnostic X-ray system can be found in which the scattered radiation grid is moved with the aid of a stepping motor. The transmission of motion is effected via a crank and a connecting rod. Electrical control of the stepping motor is necessary to assure a uniform linear motion even at the turning points of the crank. A second crank and a second connecting rod on the motor also provide a counterweight for compensating for mass in order to prevent interfering vibration.
Typically, modern diagnostic X-ray systems have a compact structure. The installation space for the scattered radiation grid is therefore limited.